Heating furnace



HEATING FURNACE 3 Sheets-Sheet l Aug. 8, 1933. A, CULBERTSON Filed March 26, 1950 1760620607 7 445:7?7 1.. CULBEETSO/V,

Aug. 8, 1933- A. L. CULBERTSON HEATING FURNACE 3 Sheets-Shet 2 Filed March 26 1930 Aug. 8, 1933.

A. L CULBERTSON HEATING FURNACE Filed March 26 1950 3 Sheets-Sheet 3 mew? 145ET A. CULBEE'TSO/V,

ids War/7 Patented Aug.8,193a3 1 I Q 1,921,507

UNITED sra'res earsu'rorrlce ZPHEATING FURNACE Albert Culbertson, Mani. Lebanon, Pa, Application March 26, 1930. Serial No. 439,051

13 (o1. see-17) This invention relates to furnaces and, while valve 9 is. provided, in each of the branch'connot limited thereto, relates more particularly to duits 8 regenerative furnaces known as soaking pits and 1 The pits 2 are provided with ports 10 in their used for the reheating of ingots'to the temperarear walls adjacent the'bottoms thereof through 5 ture necessary for forging or rolling. which the products of combustion pass from the 60 One object of this invention is to provide'a pits. By arranging the ports and the burner novel furnace construction employing a single ports in this manner, a substantially U-shaped rcgeneratcr for preheating the air for combus flame is obtained, which is advantageous. The tion in the several pits of said furnace and proports 10 communicate with branch conduits or 10 viding control means whereby each of said pits fiues '12 which in'turnare-connected to a waste 65 may be cut in or out of operation or regulated gas manifold conduit 13. A manually operated. without interrupting the operation of the other shut-off valve or damper 14 is mounted in each pits. V ofthe branch conduits lZ. v 7

Another object is to provide a combination of The gas manifo d 6 is C n d o a gas 1 1 stacks, fiues, conduits and valves whereby the ply main 15 leading from any suitable source of 70 amount of hot waste gases going to the regengas supply, such as a gas producer or a source erator may be controlled and whereby the hot of natural gas. waste gases going through the regenerator may 1 The an manifold 8 is-connected by amain hot be tempered by at least a part of'the cooledwast e air supply conduit 16 leading from the hot air gases-coming from said regenerator. outlet of a continuous regenerator 17.

The above and other objects and advantages The waste gas manifold 3 is 001111666861 by a will be more fully brought out in the following main Waste'gas conduit'or flue 18 which leads specification and illustrated in the 'accompan to? main Waste gas/Stack ing drawings in which i The regenerator 17 per se is a standard ap- Figure 1 is a plan view of 'a furnace layout c0nparatus and comprises a heat insulated, substanstructed' in accordance with this invention. tially rectangular chamber or body 20 mounted on Figure 2 is a side elevation of the furnace, parta brick or other heat' insulating base 21. The ly in section and partly broken away. chamber or body is divided into three sub-cham- Figure 3 is a sectional plan View of the pro-'- here 22 by transverse walls 23 composed of brick heater of the furnace. or other heat insulating material. Each sub- Figure 4 is a vertical transverse section through chamber is provided with a plurality of metal the preheater. v heater plates 24 which are suspended therein and Referring more particularly to the drawings, are adapted to be heated to a high temperature the numeral 2 designates the several pits of the by the hot waste gases and to give off said heat furnace, each of which is separate from the other to the airpassed through said sub-chamber. 0

and each of which is provided with a door or A hot waste gas conduit or f ue 25 is formed in closure member 3 at its top. The pits are of the the base 21 and communicates with each of the in and out variety, that is, the material is placed sub-chambers 22 through ports 26. A cooled in and taken out of the pits through the same waste gas conduit or flue 2'7 extends along the opening. Each of the pits has its rear wall, 'adtop of the chamber 20' and communicateswith jacent its top, provided with a pair of burner each of the subchaznbers 22 through ports 28;

ports 4 which open at their'rear ends into a miX- A' cold air conduit or flue 29 extends along ing chamber 5. A gas supply manifold conduit the top of the chamber 20 and communicates 6 extends along the several pits -2 and is provided with each of the sub-chambers 22 throughports 45 with branches 6 which communicate with the 30. A hot or heated air flue 31 is formed in v mixing chambers 5 through the bottom walls the base 21 and communicates with each of the thereof; Each of the branchesfi is provided sub-chambers 22 through ports 32. with a manually operated shut-off valve 7. The ports 26 and 28 of each chamber are con- An air manifold conduit 8 extends along the trolled by valve-disks 26 and 28 respectively, several'pits 2 and is provided with branch con-' mounted on a single, vertically movable valveduits i3 which lead to each of the mixing chamrod'33, while the ports 30 and 32 of each chambers 5. A pair of nozzles 9 lead from eachair' her are controlled by. valve disks 30 and 32 re-' branch conduit 8 intothe mixing chambers 5 spectively, mounted on a single, vertically movthrough the back walls thereof on a line with the able valve-rod 34. The valve-rods'33 and 34" of burner ports. 4. A manually operated shut-off each chamber are connected toa valve-rocker 35 adapted to alternately raise and lower the rods 33 and 34 so as to open and close the valves carried thereby. By thus operating the valves 26*, 28 30 and 32, hot gases are first allowed tobers 36 mounted on a shaft 37 journaled on the.

top of the regenerator 1'7 and connected by gearing 38 to a motor 39.

The cams 36 are so adjusted that the valves controlling the flow of airand waste gases will be opened and closed so that one sub-chamber is on air while one is on gas or being heated, while a thirdv sub-chamber is closed, it having been previously heated. This previously heated subchamberi's then opened to-air as the one previously. onair is reversed and put on gas. The opening of? the previously heated sub-chamber is arranged. so as to overlap the closing of the sub-chamber previously on: air so as to-not interrupt the flow of heated air. The sub-chambers are reversed' at relatively short intervals so as to maintain aconstant supply of relatively high heated air.

A branch flue conduit 40 is connected with the waste gas main l8 and the-flue 25 in the base 21 of the regenerator 1'7 to permit hot waste gases to flow into. theregenerator. A cooled waste gas conduit 41 is connected with the outlet of the flue 27 of the regenerator l7 and with the inlet port of an exhauster 42. The exhauster 42has-it's outlet or discharge port. connected'to a conduit 43 leading into a cooled waste gas stack 44..

A blower 45 is; providedifor. supplying. air-under pressure to the regenerator 17 v and has its outlet; port; connected by: a. conduit 46 with. the cold air supply conduit 29 of: the regenerator and-by a branch conduit 47 with theairsuppl'y main 16. The conduit 46- is provided with a valve 46 by which the air supply tothe re? generator may be shut 01f.

The. branch conduit 4'7 is normally'closed by a damper 48 and is only opened when it is desiredto use cold instead of preheated air for combustion.

The'hot'air main 16 is connected with-the hot air flueBl of the regenerator by a fiue 49 having a damper valve 49 therein.

The exhauster 42'andblower 45-are coupled together by a coupling shaft 50 and are operated bya single motor 51;

The mainwaste gasfiue 18 is provided with a damper- 52 at a'point between the point of connection of the branch flue'40 and the stack.i9, and this damper is operated by a standard-pressure operating control 53 operable by the pressure within the waste gas' manifold 13.

The damper 52 will operate to maintain ac0nstant pressure in the manifold 13.

Aibleeder conduit 55 connects at oneendwith the conduit. 43 and at its other end with the hot. waste gas branch flue. 40 so as to permit thebleeding of cooled waste gases into'the'hot wastegases entering. the regenerator to temper the. hot. gases, when desired.

The flow of cooled. waste gasesv through the bleeder. conduit. 55 is automatically controlled by a damper 56 operated by a thermostat or other heat responsive device 57 mounted on the regenerator 17. The heat responsive device 57 is adapted to open the damper 56 when the regenerator becomes too hot and to close the damper when said regenerator cools.

A damper 58 is mounted in the cold air supply conduit 46 and a second damper 59 is mounted in the cooled waste gas conduit 41. The damper 58 is adapted to be moved toward closed position when the pressure builds up in the air manifold 8 due to any cause such as shutting down of or reducing the air supply to one or more of the pits 2, and at the same time the damper 59 is adapted to be moved toward closed positiouso as to decrease the induced flow of' 8 varies in direct proportion to the amount of heated air used byxthe pits. Therefore the pressure control. apparatus will operate the'dampers accordance with the amount of heated air used.

The" regenerative furnace arrangement describediabove providesaconstant supply of heat- 7 ed-air for combustionand the wholecombination is automatically controlled so as to provide-air ata substantially constant pressure and temperature regardless ofthe amounts used, and said automatic control alsoprevents overheating of the regeneratorso as toprolong its life.

While I have shownand described one specific embodiment of my invention, itwill be. understood that I dornotwish to be limited thereto,

since. various-modificationsin detail may be made without departingv from. the scope thereof, as defined in the appended. claims.

I claim:

1. A? furnace of thecharacter-described! comprising. aplurality ofverticalindependent pits, a single heatexchanger, a fuel manifold communicating with each, of said pits, air manifold communicatingwith each of said pits, a waste'gas manifold communicating witheach of said pits,

flow ofrhot waste gases to said heat exchanger, a

cool-waste gas stack, a conduit communicating WllihzSfild heat exchanger and said cooled" waste gas stack to permit the cooled waste gases to escape-frornzsaid heatexchanger, means. operated by. the pressure in the air manifold for controlling the flow- Ofi cooled waste'gases throughsaidcon duit; a branch". conduit communicating with. said cooledwastegas conduit and said branch flue supplyinghot waste gases to-said heat exchanger so as to permitbleeding of cooled waste gases'into said hot-waste gases to temper saidihot gases he? fore-they enter said heat exchanger; means for controlling the flow of cooledwaste 'gaseszthrough said branchconduit, means for supplyingiairto said'heat exchanger; a heated air. fluecommunie eating with said heat exchanger and said air manifold, and'a gas supply main connected with said fuel'manifold.

2. A furnace of the character described comprising a plurality of vertical independent pits, a single heat exchanger, a fuel manifold communicating with each of said pits, an'air'manifola communicatingwith each of said pits, a waste gas manifold communicating with each of said pits, means for controlling the air and fuel flow to each of said pits, and means for opening and shutting off the communication of said waste gas manifold with each of said pits, a main stack, a stack flue for conducting the hot waste gases from said waste gas manifold to said stack, a branch flue communicating with said heat exchanger and said staclrflue for supplying hot waste gasesto said heat exchanger, means for controlling the flow of hot waste gases to said heat exchanger, a cool Waste" gas stack, anexhauster, a conduit communicating with the inlet side of said. exhauster and said heat exchanger for drawing the cooled Waste gases from said heat exchanger, a conduit communicating with the outlet side of said exhauster and said cooled waste gas'stack for delivering said cooled waste gas to said stack, means controlled by the pressure in the air mantfold for controlling the flow of cooled waste gases through said conduit leading to said exhauster, a branchconduit communicating with said conduit leading from said exhauster to said cooled waste gas stack and said flue supplying hot waste gases to said heat exchanger so as to permit bleeding of cooled Waste gases into saidhot. waste gases to temper said hot gases before they enter said heat exchanger, means for controlling the flow of cooled waste gases through said branch conduit, means for supplying air under pressure to said heat exchanger, means controlled bythe pressure in the air manifold'for controlling the amount of air supplied to the heat exchanger, and a heated air flue communicating with said heat exchanger and said air manifold.

3. A furnace of the character described comprising a plurality of vertical independent pits, a

single heat exchanger, a fuel manifold communieating with each of said pits, an air manifold communicating with each of said pits, a waste gas manifold communicating with each of said pits, means for controlling the air and fuel flow to each of said pits, and means for opening and. shutting off the communication of said waste gas manifold with each of said pits, a main stack, a stack flue for conducting the hot waste gases from said waste gas manifold to said stack, a branch flue communicating with said heat exchanger and said stack flue for supplyinghot waste gases to said heat exchanger, means controlled by the pressure in the air manifold for controlling the flow of hot waste gases through said heat exchanger, a cool waste gas stack, means for'exhausting the cooled gases from said heat exchanger and delivering said gases to said cooled waste gas stack, means controlled by the temperature of said heat exchanger for bleeding a part of said cooled waste gas into said branch flue supplying hot waste gases to said heat exchanger so as to temper said hot gases before they enter said heat exchanger,

i N means for supplying air under pressure to said heat exchanger, means for supplying heated air from said heat exchanger to said air manifold, and means for supplying gas to said fuel manifold.

4. A furnace of the character described comi prising a plurality of vertical independent pits, a

single heat'exchanger, a gas manifold communicating with'each of said pits, an air manifold communicating with each of said pits, a waste gas. manifold communicating with each of said pits, means for controlling the air and gas flow to each of said-pits, and means for opening and shutting off the communication .of said. waste gas manifold with each of said pits, a main stack, a stack flue for conducting the hot waste gases from said waste f gas manifold tosaid stack, a branch flue, communicating with said heat exchanger and said stack flue for supplying ,hot waste gases to. said heat exchanger, means for controlling the flow of hot waste gases to said heat exchanger, a cool waste gas stack, an'exhauster, a conduit communicating with the inlet side of said-exhauster and said heat exchanger for drawing the cooled waste gases from said heat exchanger, a conduit communicating with the outlet side of said exhauster and said cooled waste gas stack for delivering said cooled waste gases to 'said stack, a blower,a conduit leading from the outlet of said blower to said heat exchanger to supply air under pressure to said heat exchanger, pressure controlled'means operable by the pressurein'said air manifold for'automati-' cally controlling the flow of waste gases from said heat exchanger and the 'flowof air from' said blower to said heat exchanger, a branch conduit communicating with said conduit leading from said exhauster to said cooled waste gas stack and said flue supplying hot waste gases to said heat exchanger, so as to permit bleeding of .cooled waste gases into said hot waste gases to temper said hotfgases before they enter said heat exchanger, temperature controlled means operable by the temperatureof said heat exchanger for controllingthe flow of cooled waste gases through said branch conduit, and a heated air fluecommunicating with." said heat exchanger. andsaid 115 air manifold.

5. A furnace of the character described comprising a plurality of independent pits, a single heat exchanger, a fuel manifold communicating with each ofv said pits, an air manifold com- 120 municatingwith each of said pits, a waste gas manifold communicating with each of said pits, means for independently controlling the air and gas flow to each of said pits, means for opening and shutting off the communication of said waste gas manifold with each of said pits, means for passing hot waste gases from the waste gas manifold through the heat exchanger, means operated by the pressure in the air manifold for controlling the flow of waste gases through the heat exchanger, means for supplying air to the heat exchanger, means for conducting heatedv air from the heat exchanger to the air manifold, and means for supplying fuel to the fuel manifold.

6. A furnace of. the character described comprising a plurality of independent pits, a single heat exchanger, a fuel manifold communicating with each of said pits, an air manifold communieating with each of said pits, a waste gas manifold communicating with each of said pits, means for independently controlling the air and gas flow to each of said pits, means for opening and shutting off the communication of said waste gas manifold with each of said pits, means for passing hot waste gases from the waste gas manifold 145 through the heat exchanger, means for supplying air to the heat exchanger, means operated by the pressure in the air manifold for controlling the flow of air and waste gases through the heat exchanger, means for conducting heated air from the: heat exchanger to the air manifold, and means forsupplying gas to the fuelmanifoldi 7a A furnaceof' the character described comprising a plurality of independent pits, a single heat exchanger, a fuel manifold communicating with each of said pits, an-air manifold communicatingwithieach'of said pits, a wastegas manifold communicating with-each of saidpits; means for controlling the air and gas flow: to each of said pits-,.means for opening; and shutting off the communication of the Waste gas manifold with each of: said pits, means for passing hot waste gases from the Waste gas'manifold through the heat exchanger, means for passing air. throughv the heat exchanger, means operatedby the pressure in theair manifold for controlling'the flow of air through-the heat exchanger, means for conductingheated-air from the heat exchanger to the air manifold; andmeans for supplying gas to thefuel manifold;

8; A furnace comprising means for supplying fueland air under pressure to the furnace and for withdrawing the products of combustion therefrom and adapted to form a substantially U- sh'aped'flame in said furnace, a regenerator for preheating theair suppliedto the furnace; and means-controlled by the pressure of the entering air for controlling the amount of air and waste gases passing through the regenerator.

9. A- furnace comprising a plurality of in and out pits, means forsupplying fuel and air. under pressure to each of said pits, manually operable valves for individually regulating the amount of fuel and'air'supplied to each of said'pits, a single regeneratorfor preheating the air supplied to the pits, and means regulated by the pressure of air entering the pits for automatically controlling the amount of air passed throughtthe regenerator and supplied to the pits.

10..A1furnace comprising a plurality of in and out pits, means for supplying fueland air under pressure to each of said pits, manually. operable valves for individually regulating the amount of: fuel and'air supplied to each of said pits, a single regenerator for preheating the: air supplied to the pits,.means-for passing waste gases from the pits through-the regenerator, and means regulated by the' pressure of air entering the pits-for automatically controlling the amount of waste gases and air passing through the regenerator 1-1. A pit furnace of the character described comprising means for supplying fuel and air to the furnace and for'withdrawing' waste gases therefrom, a heat exchanger for transferring heat from said Waste gases to the air supplied'to the furnace, and means controlled by. the pressure of the-air supplied to the furnace for regulating the amount of Waste gases passed through the heat exchanger.

12; A pit furnace of the characterdescribed comprising means for supplying fuel and air to the furnace and for withdrawing waste, gases therefrom, a heat exchanger for transferring heat from said waste gases to the air supplied to the furnace, and means controlled bythe pressure of the air supplied to the furnace for 'regu lating the amount of air andwaste gases passed through the heat exchanger.

13. A furnace of the character described, comprising a plurality of independent pits adapted to be simultaneously operated, means forsupplying fuel and air under pressure to each ofsaid pits and for withdrawing the products of combustion therefrom; including an airmanifold; a single regenerative system for preheating the air supplied to'all of said pits, and means controlled by the-pressure in the air manifold for regulating the amount of air and waste gases passing through the regenerative system.

ALBERT L. CULBERTSQN. 

